Insulated concrete form

ABSTRACT

A concrete form consisting of a metallic sheath (20) having a front (22), top (24), back (26), and an angular locking flange and bug barrier (28) nesting over an insulated barrier (30). The sheath (20) is permanently attached to the barrier (30) with a heating adhesive material (31) set by rotatably compressing the assembly between two rollers. Corners are made by notching the sheath (20) on one of the sides and adding a metallic corner splice angle (32). Longitudinal splice joints utilize a straight splice angle (34) inserted between the sheath (20) and barrier (30), where the two ends butt together. Conventional prepositioned wooden stakes (36) are held tightly against the outside surface of the concrete form with wire form clips (38). A metallic sill plate (40) may be added to the structure after the concrete has been poured into the form and hardened. Only the stakes (36) and clips (38) need to be removed, as the remainder of the form becomes an integral part of the floor structure.

TECHNICAL FIELD

The invention relates to building structures, in general and morespecifically to concrete forms used in construction of slab floors andstem wall insulation.

BACKGROUND ART

The current method used for constructing concrete slab floors is toinitially set into the ground a plurality of wooden stakes around theouter periphery of the unpoured slab. A reusable wood form is nextattached to the stakes by means of nails or screws. To the insidesurface of the form is placed an insulation barrier that is attached tothe forms by means of an adhesive and/or special nails. After thecomposite form is securely in place, the concrete slab is poured.

Once the concrete slab has set and hardened, the wood form is manuallyremoved from the insulation barrier and the stakes. The exposedinsulation barrier is then covered with a metal sheath that is placedover the top of the barrier.

A search of the prior art did not disclose any patents that directlyread on the claims of the instant invention. However, the following U.S.patents were considered related:

    ______________________________________                                        U.S. PAT. NO. INVENTOR     ISSUED                                             ______________________________________                                        4,340,200     Stegmeier    20 July 1982                                       4,141,532     Wall         27 February 1979                                   4,027,846     Caplat       7 June 1977                                        3,016,225     Hughes       9 January 1962                                     ______________________________________                                    

The Stegmeier patent approaches the problem of holding a form board inplace to a support stake with a U-shaped spring clip. This clip containsfingers to grasp the top and bottom edge of the form while applyingpressure to a round stake. The clip is in two separate pieces one toattach to the board and the other to apply spring pressure to the stake.

The Wall patent discloses an extruded U-shape frame that is castintegral with the edge of a flat concrete building panel and becomes theedge molding for attachment to a wall. Connecting means are incorporatedinto this molding with corner frame members completing the structure.

The Caplat patent utilizes a panel for casting concrete walls. The panelhas steel sheets on the front and rear and rigid polyurethane foam castin situ between the panel walls. The utility lies in weight andself-heating of the concrete in that the low thermal conductivitypermits the heat generated in curing to be retained permitting a rapidsetting of the concrete. The panel is removed when the concrete is set.

The Hughes patent discloses an attaching lever to retain a form and lockit into place with an over center cam-lock lever compressibly holding ahollow stake. A support channel contains top and bottom flanges thatretain the wooden form and the attaching lever.

For background purposes and as indicative of the art to which theinvention relates, reference may be made to the following U.S. patents:

    ______________________________________                                        U.S. PAT. NO.  INVENTOR     ISSUED                                            ______________________________________                                        4,022,437      French       10 May 1977                                       3,595,515      Rollow       27 July 1971                                      2,741,821      Findley      17 April 1956                                     ______________________________________                                    

DISCLOSURE OF THE INVENTION

Costs involved in constructing inhabital structures has increasedconsiderably, therefore, the need to reduce materials costs and providemethods to reduce manpower requirements has become an important factorin the building trade. Also, when constructing a slab floor certaingovernment regulations have required an insulation barrier andprotective metal covers to be added in critical areas in order toconserve energy. The addition of these requisite items is cosly andlabor intensive. Therefore, it is the primary object of this inventionto provide a concrete form that has sufficient structural integrity topreclude the use of wood forms entirely and incorporate the insulationbarrier and metal protective cover in a single and permanent structure.Previously, slab floors, as well as stem wall insulated construction,required wood forming using a 2×8, 2×10, or 2×12 (41.3 mm wide ×193.7 to295.3 mm high) board. These wood boards would be positioned around theperiphery with stakes driven into the ground and nailed partiallythrough to hold them in place during the pouring and hardening process.

The fact that no labor is required to strip out the forming aftercasting is indeed an important object, as the instant invention allowsthe forming to stay in place once the concrete has been poured.Stripping by hand requires pulling the nails from the stakes thenremoving them from the ground and carefully breaking the wood itselfaway. Further, cleaning and storage, plus transportation to the next jobsite all requiring considerable manual labor to accomplish.

Another object of the invention includes the application of a reusablewire form stake clip to hold the stake to the concrete form eliminatingthe need for nails completely. The use of this novel stake clip allowsan expedient and simplified form laying technique where wood stakes areinitially and conventionally positioned around the outer periphery ofthe unpoured slab. After the stakes are in place the insulated concreteform is laid against the inner side of the stakes and the stakes areeasily locked to the form by means of the stake clip.

Prior art utilizes a separate temporary attachment of the requiredinsulation to the wood form by nailing, stapling, or glueing theinsulation to the wood as previously discussed. The slab is then pouredand when the wood form is taken off, extreme care is used to not damagethe surface so attached. Further, it is necessary to add a metalprotective cover over the insulation so that it extends below grade andattaches to the structure above the concrete slab. It is, therefore,still another object to eliminate this step completely as the inventionin the preferred embodiment includes all of these procedures prior toinstallation completed at a convenient location where the insulation isbonded to the metallic protective sheath and then handled as an integralcomponent.

Yet another object allows flexibility of shape of the footing, as thelengths may be easily cut with a portable electric saw with a rotatingblade. Right angle joints are also easily made by notching the metal onone side of the joint and adding a corner splice angle between theinsulation and the metal. Similarly, butt joints are formed bypositioning the form end to end and adding a metallic splice angle inthe same manner.

The final object allows all of the requisite government statutoryrequirements to be satisfied, such as Title 24 of the California EnergyCommission, a state law requiring energy conservation in residentialbuilding. These requirements specify the need for the insulation alongwith a minimum "R" factor (heat transfer coefficient) which theinvention completely adheres to in its entirety.

These and other objects and advantages of the present invention willbecome apparent from the subsequent detailed description of thepreferred embodiment and the appended claims taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial isometric view of the corner of the preferredembodiment with the protective sheath partially cut-away for clarity.

FIG. 2 is a partial isometric view of the corner shown from the sideopposite FIG. 1.

FIG. 3 is an exploded partial isometric view of the corner as shown inFIG. 2.

FIG. 4 is a fragmentary view in partial isometric of the invention at abutt joint cut-away to depict the splice angle inserted between thesheath and the block foam.

FIG. 5 is a partial isometric view of the straight splice angle removedentirely from the assembly.

FIG. 6 is a cross-sectional view of the preferred embodiment includingthe soil, slab floor and footing.

FIG. 7 is a partial isometric view of the wire form stake clip removedfrom the invention for clarity.

FIG. 8 is the front side of a stake with the wire form clip installedcompletely removed from the assembly.

FIG. 9 is the rear side of the above stake.

FIG. 10 is a fragmentary cross-sectional view of the insulated concreteform illustrating the sill plate water barrier installed thereupon.

FIG. 11 is a partial isometric view of the insulated concrete form as itwould be assembled ready for processing, including butt joints andcorners, however, removed from the ground.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now in detail to the drawings and describing the preferredembodiment, the invention comprises a self-contained insulated form forconcrete having a metallic protective sheath 20 in linear shape. Thesheath 20 is formed from sheet metal angularly broken into aconfiguration having a vertical front leg 22, a horizontal top 24, avertical back 26 and an angular locking flange and bug barrier 28, asshown in FIGS. 1-4. The sheath 20 is formed of metal, such as hot orcold rolled steel, or sheet aluminum. A low carbon grade of rimmed,capped steel or semi-killed steel preferred, and a uniform layer of zincapplied by an electro-plated process. Painted or hot dipped galvanizedsurface treating is also acceptable. The steel with either a heavy orflash coating of zinc allows the paint to adhere without costly cleaningand surface preparation. It has been found that Republic Steels materialknown by its registered trademark "PAINTLOK" in 26 gauge, 0.040 inches(1.016 millimeters) is an ideal material to use. In practice, the sheathis formed by slitting the material from a roll, flattening and formingin sections in a press brake creating a structural member of a lengtheasy to handle.

An insulated barrier 30 nests into the protective sheath 20. Thisbarrier 30 is made of rigid block foam insulation in linear rectangularshape and has a front, back, top, and bottom. The length of this barrier30 is exactly the same as the sheath 20 and is perhaps twice as high asthe sheath vertical front leg 22. The width is the same as the inside ofthe sheath top 24 and back 26 allowing a tight fit when nested together.The barrier 30 is formed of a rigid block foam insulating material, suchas polyurethane foam in the closed cell formulation, or celluloseacetate, phenolics or urea formaldehyde. Polyvinyl chloride in thestyrene acrylonitrile type may also be utilized with polystyrene beingpreferred, best known by its registered trademark "STYROFOAM". Thismaterial is well known in the art and is molded from expandable beadsinto rigid finished boards. When nested together with the sheath 20, thebarrier 30 is partially contiguous on the front to the sheath front leg22, also on the top to the sheath horizontal top 24 and the upperportion of the back to the sheath back 26, all being in intimate contactwith their respective mating surfaces.

An adhesive material 31 bonds the sheath 20 to the insulation 30. Thiselastomeric material may include blends of natural rubber Buna-N orresin, such as phenolic-butadiene-acrylonitrile rubber with an elastomerknown by its registered trademark "STAVON" in the formulation T440 REDbeing preferred. This adhesive material is preheated and sprayed on boththe inside surface of the sheath 20 and the insulation barrier 30 andjoined together while still in the liquified state. The entire assemblyis then placed between two rollers the exact shape of the material androtatably compressed to set fast the adhesive therebetween.

When thus assembled, the form becomes a rigid member that is easilyhandled and transported to the job site.

A corner is made, at any angle, by notching the sheath top 24 and theback 26 the same distance as the width of the assembly when placed atright angles to an unnotched form. The angular locking flange 28 isnotched somewhat deeper allowing clearance for its counterpart. When thenotched and unnotched forms are angularly together the entire outsidesurface is covered with metal without overlapping or exposing theinsulated barrier 30. To secure this joint a metallic corner spliceangle 32 is utilized. This splice angle 32 has two flat surfaces and isbroken on the length forming a corner. The height of the splice angle 32is the same as that of the leg 22, but shorter in length, and isinstalled by forcing each flat surface into the glued interface betweenthe sheath vertical leg 22 and the insulated barrier 30. This forceableentry tears away the glue from the joint, however, sufficientcompression is left to maintain the integrity of the junction. Thiscorner construction further acts as structural reinforcing andcompletely seals the apex of the corner.

A splice joint for a long run of form is similarly constructed with theends of the insulated concrete forms butted together in linearalignment. A metallic straight splice angle 34 having a top leg and avertical leg are likewise inserted into the interface of the top 24, thefront leg 22, and the barrier 30. The top leg of the splice angle 34 isthe same length, or shorter, than inside of the barrier top 24 and thevertical leg matches the inside height of the front leg 22, therebyclosing the gap between the butt jointed forms. Compression is alsomaintained as above. During the insertion process no ancillary tools arerequired for either angle 32 or 34, as the corner is started and forcedinto squareness, also the insulation barrier 30 has a memory whenseparated. Adhesive may be added during this assembly process, but isunnecessary for proper stability of the form.

Stakes 36, well known in the art, are utilized to hold the form to theground and maintain the forms position when concrete is poured withinthe outline. These stakes 36 are made of wood with the bottom end cut toa point and are positioned on the outside of the form. A wire form stakeclip 38 holds the stake 36 tightly against the form. One end of the clip38 corresponds in shape to the sheath vertical back 26, top 24, andfront 22, with an angular offset parallel to said sheath 20 front leg22. The other end, or bottom portion, is angularly disposed even withthe bottom of the front leg 22 extending upward parallel with the sheath20. This clip 38 compressibly secures the stake 36 to the metallicprotective sheath 20 at the front leg 22. The top of the clip iscompressibly slid over the top of the sheath 20 and the bottom isimpinged into the barrier 30 slideably holding the stake 36 closelyagainst the sheath 20. The use of the clip 38 allows the stake 36 to beinitially set into the ground and the form to be easily and convenientlylocked to the stake 36 by the clip 38. When the concrete is poured andhardens the wire form clip 38 and stake 36 are removed. The barrier 30and sheath 20 then become an integral part of the structure.

To maintain a water barrier, a metallic sill plate 40, pictoriallyillustrated in FIG. 10, is added to the structure after the concrete ishardened and the stakes 35 are removed. This sill plate 40 is of thesame material as the sheath 20 and is in a "Z" configuration. In abuilding using a slab floor construction, a wood plate 42 is attachedaround the periphery of the slab upon which the wall is formed. Thissill plate 40 is attached to the wooden plate 42 and rests on the top 24and front 22 of the sheath 20. Again, adhesive or waterproofing masticmay be applied, if desired, to the interface. The purpose of this memberis to prevent water, or moisture in various forms, from penetrating thestructure.

FIGS. 6 and 10 illustrate the position of the structure in relation tothe concrete slab floor and footing 44, and the adjacent earth 46. Itwill be noted that after the concrete has set and hardened the entirecomposite assembly, except for the stakes 36 and wire form 38, become anintegral part of the floor. Not only does the concrete adhere to thesurface of both the sheath 20 and barrier 30, but also to the angularlocking flange and bug barrier 28 which is persistently secured withinthe aggregate. The top of the form is planar with the horizontal surfaceof the slab completing the structure in that phase of the constructionprocess.

The methods described above for a slab floor are basically the same fora stem wall insulation type of construction, with only the configurationvarying slightly.

The steps of constructing a floor using this method of forming include:forming a metallic protective sheath 20 in linear shape, as previouslydescribed, slitting rigid block foam into a rectangular shapedinsulating barrier 30, heating and spraying adhesive into correspondingareas of the sheath 20 and insulating barrier 30, nesting and joiningthem together by rolling.

The corners are made by notching one of the ends of the sheath 20 andinserting a corner splice 32 into both open ends. Likewise, a splice ina straight run of forming is made by inserting a splice angle 34 intoeach butted end creating a structural joint.

Stakes 36 are then positioned around the outer periphery of the unpouredslab and the form is compressibly secured to the inner side of the stake36 by means of the stake clip 38.

It will be observed that with this type of concrete form, variousperiphial outlines may be obtained as internal or external corners maybe angularly provided, also straight long runs are easily accomplishedwith the splice joint thus described.

While the invention has been described in complete detail andpictorially shown in the accompanying drawings, it is not to be limitedto such details, since many changes and modifications may be in theinvention without departing from the spirit and the scope thereof.Hence, it is described to cover any and all modifications and formswhich may come within the language and scope of the claims.

I claim:
 1. An insulated concrete form for slab flooring comprising:(a)a metallic protective sheath in linear form having a vertical front leg,a horizontal top, a vertical back, and an angular locking flange and bugbarrier; (b) an insulated barrier of rigid block foam in linearrectangular shape having a front, back, top, and bottom, partiallycontiguous on the front with said sheath vertical front leg, the topcontiguous with said sheath horizontal top, and the upper portion of theback contiguous with said sheath vertical back, all being in intimatecontact; (c) adhesive bonding said protective sheath to said insulatedbarrier in constant relationship defining a self-contained permanentform to receive concrete in the liquified state when poured into a slabfloor configuration becoming an integral part of the periphery when theconcrete is solidified with said angular locking flange and bug barriersecured within the concrete and the top planar with the horizontalsurface of the slab; and, (d) an angular corner formed by notching saidsheath horizontal top, vertical back, and angular locking flange of onelinear form in such a manner as to abut with an unnotched form at rightangles having said sheath covering the entire corner without overlappingor exposing said insulated barrier.
 2. An insulated concrete form forslab flooring comprising:(a) a metallic protective sheath in linear formhaving a vertical front leg, a horizontal top, a vertical back, and anangular locking flange and bug barrier; (b) an insulated barrier ofrigid block foam in linear rectangular shape having a front, back, top,and bottom, partially contiguous on the front with said sheath verticalfront leg, the top contiguous with said sheath horizontal top, and theupper portion of the back contiguous with said sheath vertical back, allbeing in intimate contact; (c) adhesive bonding said protective sheathto said insulated barrier in constant relationship defining aself-contained permanent form to receive concrete in the liquified statewhen poured into a slab floor configuration becoming an integral part ofthe periphery when the concrete is solidified with said angular lockingflange and bug barrier secured within the concrete and the top planarwith the horizontal surface of the slab; and, (d) an angular cornerformed by notching said sheath horizontal top, vertical back, andangular locking flange of one linear form in such a manner as to abutwith an unnotched form at right angles having said sheath covering theentire corner without overlapping or exposing said insulated barrier;and (e) a metallic corner splice angle having two flat surfaces at rightangles forceably embracing the interface between said sheath verticalleg and said insulated barrier being the same width as said sheathvertical leg and smaller in length creating a structural corner wheninserted therebetween reinforcing the formed junction.
 3. An insulatedconcrete form for slab flooring comprising:(a) a metallic protectivesheath in linear form having a vertical front leg, a horizontal top, avertical back, and an angular locking flange and bug barrier; (b) aninsulated barrier of rigid block foam in linear rectangular shape havinga front, back, top, and bottom, partially contiguous on the front withsaid sheath vertical front leg, the top contiguous with said sheathhorizontal top, and the upper portion of the back contiguous with saidsheath vertical back, all being in intimate contact; (c) adhesivebonding said protective sheath to said insulated barrier in constantrelationship defining a self-contained permanent form to receiveconcrete in the liquified state when poured into a slab floorconfiguration becoming an integral part of the periphery when theconcrete is solidified with said angular locking flange and bug barriersecured within the concrete and the top planar with the horizontalsurface of the slab; and, (d) an angular corner formed by notching saidsheath horizontal top, vertical back, and angular locking flange of onelinear form in such a manner as to abut with an unnotched form at rightangles having said sheath covering the entire corner without overlappingor exposing said insulated barrier; (e) a metallic corner splice anglehaving two flat surfaces at right angles forceably embracing theinterface between said sheath vertical leg and said insulated barrierbeing the same width as said sheath vertical leg and smaller in lengthcreating a structural corner when inserted therebetween reinforcing theformed junction; and, (f) a splice joint formed by butting a pair ofinsulated concrete forms end to end and attaching a metallic straightsplice angle having a top leg and a vertical leg forceably embracing theinterface between said sheath top and sheath vertical front leg beingthe same width as the inside of said sheath top and front leg creating astructural joint when inserted therebetween reinforcing the formedjunction.